ofr 2013-06 thin section analysis of core samples from the duvernay and muskwa formations and the...

AER/AGS Open File Report 2013-06

Thin Section Analysis of Core Samples from the Duvernay and Muskwa Formations and the Majeau Lake Member in Alberta

AER/AGS Open File Report 2013-06

Thin Section Analysis of Core Samples from the Duvernay and Muskwa Formations and the Majeau Lake Member in Alberta

S.D.A Anderson1, J. Bladek2, and C.D. Rokosh1

1 Alberta Energy Regulator Energy Resource Appraisal

2 Calgary Petrographics Ltd.

August 2013

AER/AGS Open File Report 2013-06 (August 2013) • iii

©Her Majesty the Queen in Right of Alberta, 2013ISBN 978-1-4601-0101-8

The Alberta Energy Regulator/Alberta Geological Survey (AER/AGS), its employees and contractors make no warranty, guarantee or representation, express or implied, or assume any legal liability regarding the correctness, accuracy, completeness or reliability of this publication. Any references to proprietary software and/or any use of proprietary data formats do not constitute endorsement by AER/AGS of any manufacturer’s product.

If you use information from this publication in other publications or presentations, please acknowledge the AER/AGS. We recommend the following reference format:

Anderson, S.D.A., Bladek, J., Rokosh, C.D. (2013): Thin section analysis of core samples from the Duvernay and Muskwa formations and the Majeau Lake Member in Alberta; Alberta Energy Regulator, AER/AGS Open File Report 2013-06, 58 p.

Author addresses:J. BladekCalgary PetrographicsPO Box 39Tusket, NS B0W 3M0Canada902.648.2323E-mail: [email protected]

Published August 2013 by:Alberta Energy RegulatorAlberta Geological Survey4th Floor, Twin Atria Building4999 – 98th AvenueEdmonton, AB T6B 2X3Canada

Tel: 780.422.1927Fax: 780.422.1918E-mail: [email protected]: www.ags.gov.ab.ca

mailto:AGS-Info%40ercb.ca?subject=

http://www.ags.gov.ab.ca

AER/AGS Open File Report 2013-06 (August 2013) • iv

ContentsAcknowledgements ........................................................................................................................................vAbstract ........................................................................................................................................................ vi1 Introduction .............................................................................................................................................12 Sample Locations and Descriptions ........................................................................................................23 Analytical Methods and Results ..............................................................................................................4

3.1 Thin Section Preparation ................................................................................................................43.2 Thin Section Analysis ....................................................................................................................4

3.2.1 Grain-Size Distribution, Mineralogy, and Organic Matter .................................................43.2.2 Primary Sedimentary Structures, Secondary Structures, and Porosity...............................53.2.3 Sample Descriptions ...........................................................................................................53.2.4 Errors and Assumptions ......................................................................................................6

4 Summary .................................................................................................................................................65 References ...............................................................................................................................................7 Appendices

1 Sample Locations and Descriptions ........................................................................................................82 Thin Section Descriptions .....................................................................................................................10

TablesTable 1. ERCB publications related to shale- and siltstone-hosted hydrocarbon resource assessment

in Alberta. ......................................................................................................................................1Table 2. Thin section sample sites. ..............................................................................................................2

FiguresFigure 1. Thin section sites sampled for the Duvernay and Muskwa formations and the

Majeau Lake Member. ...................................................................................................................3Figure 2. Illustrative chart showing the range of sphericity and roundness for silt- and

sand-sized grains. ..........................................................................................................................5

AER/AGS Open File Report 2013-06 (August 2013) • v

AcknowledgementsThe Alberta Energy Innovation Fund, through Alberta Energy, has funded this project. The authors thank C.L. Schneider, from the University of Alberta for technical editing of the thin section descriptions and D.J. Bechtel and M. Grobe from the Alberta Energy Regulator for their editing contributions.

AER/AGS Open File Report 2013-06 (August 2013) • vi

AbstractThis report is a release of thin section descriptions from the Duvernay and Muskwa formations and the Majeau Lake Member of the Western Canada Sedimentary Basin. These were generated for the ongoing Energy Resources Conservation Board (now Alberta Energy Regulator) project on shale- and siltstone-hosted hydrocarbon resources in Alberta.

Thin sections were created by laboratories to our specifications for very fine grained, transmitted-light microscopy. The analysis of each thin section included visual estimations (in per cent) of grain-size distribution, mineralogy, cement, allochems, opaque material, and organic material. Physical and biogenic sedimentary structures, fractures, and porosity were identified and described if present. General sample descriptions, rock classifications, and microphotographs are included for each sample.

AER/AGS Open File Report 2013-06 (August 2013) • 1

1 IntroductionThe Energy Resource Appraisal (ERA) Group of the Alberta Energy Regulator (AER), formerly the Energy Resource Conservation Board (ERCB), initiated a project in 2007 to evaluate shale gas resources in Alberta to determine the quantity and spatial extent of these resources. Since then, this project has expanded to include shale- and siltstone-hosted hydrocarbons (oil, gas, and natural gas liquids) in the province. The ERA is releasing reports and digital data to disseminate knowledge from the project. These data and reports can be accessed from the Alberta Geological Survey (AGS) website (http://www.ags.gov.ab.ca/publications). Table 1 lists the Open File Reports and datasets for this continuing project.

This report disseminates results from the analysis of thin sections from the Duvernay and Muskwa forma-tions and the Majeau Lake Member. The data generated from the project have been combined with addi-tional data to map and estimate shale- and siltstone-hosted hydrocarbon resources in Alberta (Rokosh et al., 2012).

Report Code Title

DIG 2013-0003

Rock Eval and Total Organic Carbon of Sedimentary Rocks in Alberta

OFR 2012-06

Summary of Alberta’s Shale- and Siltstone-Hosted Hydrocarbon Resource Potential

OFR 2010-07

Organic Petrography of the Mont-ney Formation in Alberta: Shale Gas Data Release

OFR 2010-06

Organic Petrography of the Duvernay and Muskwa Forma-tions in Alberta: Shale Gas Data Release

OFR 2010-05

Rock Eval, Total Organic Carbon and Adsorption Isotherms of the Montney Formation in Alberta: Shale Gas Data Release

OFR 2010-04

Rock Eval, Total Organic Carbon and Adsorption Isotherms of the Duvernay and Muskwa Forma-tions in Alberta: Shale Gas Data Release

OFR 2010-03

Mineralogy, Permeametry, Mercu-ry Porosimetry, Pycnometry and Scanning Electron Microscope Imaging of the Montney Forma-tion: Shale Gas Data Release

OFR 2010-02

Mineralogy, Permeametry, Mer-cury Porosimetry, Pycnometry and Scanning Electron Micro-scope Imaging of Duvernay and Muskwa Formations: Shale Gas Data Release

Report Code Title

OFR 2008-14

Mineralogy, Permeametry, Mer-cury Porosimetry and Scanning Electron Microscope Imaging of the Colorado Group: Shale Gas Data Release

OFR 2008-13

Mineralogy, Permeametry, Mer-cury Porosimetry and Scanning Electron Microscope Imaging of the Banff and Exshaw Forma-tions: Shale Gas Data Release

OFR 2008-12

Rock-Eval, Total Organic Car-bon, Adsorption Isotherms and Organic Petrography of the Banff and Exshaw Formations: Shale Gas Data Release

OFR 2008-11

Rock Eval, Total Organic Carbon, Adsorption Isotherms and Organ-ic Petrography of the Colorado Group: Shale Gas Data Release

OFR 2008-10

Geochemical and Sedimento-logical Investigation of Banff and Exshaw Formations for Shale Gas Potential: Initial Results

OFR 2008-09

Geochemical and Sedimentologi-cal Investigation of the Colorado Group for Shale Gas Potential: Initial Results

OFR 2008-08

What is Shale Gas? An Introduc-tion to Shale-Gas Geology in Alberta

Table 1. ERCB publications related to shale- and siltstone-hosted hydrocarbon resource assessment in Alberta.

http://www.ags.gov.ab.ca/publications

http://www.ags.gov.ab.ca/publications

http://www.ags.gov.ab.ca/publications/abstracts/DIG_2013_0003.html

http://www.ags.gov.ab.ca/publications/abstracts/OFR_2012_06.html















2 Sample Locations and DescriptionsTable 2 lists the thin section sample sites. Figure 1 displays sample sites associated with the Duvernay and Muskwa formations and the Majeau Lake Member thin sections. Appendices 1 and 2 provide detailed sample location and description information.

Site No. Location – UWIStratigraphic Unit Depth (m) Lithology

No. of Thin Sections

D01 100/06-14-037-07W5/00 Duvernay 3649.7 shale 1D06 100/02-06-047-04W5/00 Duvernay 2639.6 calcareous shale 1D07 100/14-29-048-06W5/00 Duvernay 2655.7 calcareous shale 1D10 100/09-06-052-11W5/00 Duvernay 3020.1 calcareous shale 1D11 100/10-30-053-14W5/00 Majeau Lake 3172.8 shale 1D15 100/10-09-059-11W4/00 Duvernay 797.7 lime mudstone 1D21 100/10-13-063-12W5/00 Majeau Lake 2625.5 calcareous shale 1D22 100/10-05-065-15W5/00 Duvernay 2752.0 shale 1D23 100/04-33-068-22W4/00 Duvernay 1054.6 lime mudstone 1D30 100/11-17-088-03W6/00 Muskwa 2319.3 shale 1D31 100/02-30-088-04W6/00 Muskwa 2401.2 shale 1D34 100/02-04-126-11W6/00 Muskwa 1517.4 shale 1D50 100/12-12-057-22W5/00 Duvernay 3881.7–3902.1 shale 4

Table 2. Thin section sample sites.


!(!(

!(

R1 W4R10R1 W5 R20R10R1 W6 R20R10

T1

T10

T20

T30

T40

T50

T60

T70

T80

T90

T100

T110

T120

T60

T70

T80

T90

T100

T110

T120

R1 W4R10R20R1 W5

Thin section sample site

Reef/carbonate platform (Switzer et al., 1994)

Urban area

0 75 150 225 300 375 km

Duvernay/Muskwa/Majeau Lake

Peace RiverArch

Grosmont Carbonate

Platform

Southern Leduc Shelf

Deformed Belt

D7D6

D1

D34

D31 D30

D23

D22D21

D11 D10

D50D15

Figure 1. Thin section sites sampled for the Duvernay and Muskwa formations and the Majeau Lake Member.


3 Analytical Methods and ResultsThis report contains thin section descriptions from core samples of the Duvernay and Muskwa formations and the Majeau Lake Member. We selected 16 samples from 13 sites for thin section analysis. Of these samples, 11 are from the Duvernay Formation, 3 are from the Muskwa Formation, and 2 are from the Majeau Lake Member. We initially analyzed the thin sections to determine the desired reporting method and to create a template for descriptions. Using this template, initial descriptions, images, and interpretations were done by J. Bladek of Calgary Petrographics Ltd. Final technical revisions were done by ERA staff.

3.1 Thin Section PreparationThin section preparation for laboratory analysis underwent a series of modifications to maximize viewable shale details. Traditional thin sections are typically ground to ~30 microns thick, which is good for examining silt or sand laminations but poor for observing details in the clay-sized particle range. Our initial investigations in grinding sections to ~20 microns thick revealed concerns about grains being plucked during grinding and polishing. For the second round, sections were first ground to ~30 microns, and then one-half of the section was wedged to just a few microns thick. The wedge successfully created an observation area for the clay-sized particles, but this area was still less then one third of the thin section surface, and images were poor due to the wedge effect. On the third round, an independent lab was contracted to test-grind the thin sections to an even thickness of ~20 microns to maximize the observable area of the slide and minimize the destruction of features due to plucking or smearing. In the end, the following steps were taken for thin section preparation:

1) The sample was coated and impregnated (if impregnation was possible) with epoxy to maintain the sample’s integrity.

2) Sections were ground to ~18–20 microns thick and polished to a low polish.3) One-half of the thin section was stained with alizarin red and potassium ferricyanide to identify

carbonate minerals.

Thin sections that were previously prepared to ~30 microns thick were sent to Calgary Rockworks Inc. to be repolished to ~20 microns and wedged, if possible. These thin sections were not as well prepared as newer versions because they were not coated and impregnated with epoxy before the sample was mounted on the slide, creating slides of reduced quality. The quality of each thin section is documented in the sample descriptions.

3.2 Thin Section AnalysisThin sections were analyzed for the following elements:

• grain-size distribution,• mineralogy,• organic-matter distribution,• primary and secondary structure,• porosity (if visible), and• any other notable characteristics.

3.2.1 Grain-Size Distribution, Mineralogy, and Organic MatterA visual estimate of the percentage of sand-, silt-, and clay-sized grains; the mineralogy of these grains; and the percentage of organic matter are based on thin section and hand-sample observation. Estimates


of the percentage of clay-sized particles are aided by examining results from energy-dispersive X-ray or X-ray diffraction data for the samples. For carbonate rocks, micritic textures were recorded as a visually estimate per cent under clay-sized grains. Some factors that affect the error in visual estimates include the thickness of the thin section compared to the average grain size of the sample and the overall quality of the thin section. Where the thin sections are excessively thick, constituents may be overestimated. Where thin section quality is poor from excessive etching of sample material during staining, underestimation of constituents is likely.

For thin sections that contain 10% silt- and sand-sized grains combined; the roundness, sphericity and sorting were observed and recorded. Figure 2 is an illustration of the sphericity and roundness chart used in this analysis.

3.2.2 Primary Sedimentary Structures, Secondary Structures, and PorosityWhen making observations about structures and porosity, the main goal is to record bedding, laminations, and fractures. Although the presence of porosity was also noted for each sample, it is dependent on impregnation of epoxy into the sample, which was extremely difficult due to the low permeability of these rocks.

3.2.3 Sample DescriptionsAppendix 2 contains thin section photographs and descriptions. A description of each sample includes the type of shale lamination present (as described by O’Brien and Slatt, 1990), the presence of any trace fossils, and any other notable characteristics. Images of some of the more interesting features are included. In addition, one or more rock names are given to each sample based on a variety of naming conventions (Folk, 1974; Dunham, 1962 cited in Embry and Klovan, 1972) and the type of sample observed. The naming convention for the sample is listed in the description table.

High

Low

Angular Subangular Subrounded Rounded

Roundness

Sphe

ricity

Figure 2. Illustrative chart showing the range of sphericity and roundness for silt- and sand-sized grains. Chart is modified from Krumbein and Sloss (1963).


3.2.4 Errors and AssumptionsThin section analyses for very fine grained rocks are problematic because it is very difficult to see the optical characteristics of very fine grained components under the transmitted light microscope. For this reason, data from other analyses we conducted—such as X-ray diffraction, X-ray fluorescence, scanning electron microscope imaging, inorganic geochemistry, and organic geochemistry—were examined for each formation to aid in thin section descriptions. Each component or mineral was visually estimated to give a general comparison to the other components. Point counting was not used to accomplish this.

Several problems were encountered during thin section creation. These included the following:

• plucking of larger grains from the finer grained matrix when polishing,• scratching of the sample when polishing,• dragging of grains when polishing to a wedge,• erosion of large amounts of material when staining, and• removal of stain when repolished.

4 SummaryAs part of the ERCB project on shale- and siltstone-hosted hydrocarbon resources in Alberta, thin section analyses were conducted on 16 samples consisting of shale, wackestone, and carbonate mudstone samples from the Duvernay and Muskwa formations, and the Majeau Lake Member. We visually estimated grain-size distribution, mineralogy, cement, allochems, opaque material, and organic material. The analyses included information on sedimentary structures, fractures, rock classification, and included photomicrographs of each sample. These descriptions are provided as a resource for geological research on these units in the Western Canada Sedimentary Basin in Alberta.


5 ReferencesDunham, R. J. (1962): Classification of carbonate rocks according to depositional texture; in

Classification of carbonate rocks: American Association of Petroleum Geologists memoir, W.E. Ham (ed.), p. 108–121.

Embry, A. F. and Klovan, J. E. (1972): Absolute water depth limits of late Devonian paleoecological zones; Geol. Rundsch., v. 61, Fig. 5, p. 676.

Folk, R.L. (1974): Petrology of sedimentary rocks; Hemphill Publishing Company, Austin, Texas, 182 p.

Krumbein, W. C. and Sloss, L. L. (1963): Stratigraphy and sedimentation, second edition; Northwestern University, Department of Geology, W. H. Freeman and Company, San Francisco and London, 660 p.

O’Brien, N.R. and Slatt, R.M. (1990): Argillaceous rock atlas; Springer-Verlag, New York, New York, 141 p.

Rokosh, C.D., Lyster, S., Anderson, S.D.A., Beaton, A.P., Berhane, H., Brazzoni, T., Chen, D., Cheng, Y., Mack, T., Pana, C. and Pawlowicz, J.G. (2012): Summary of Alberta’s shale- and siltstone-hosted hydrocarbon resource potential; Energy Resources Conservation Board, ERCB/AGS Open File Report 2012-06, 327 p., URL <http://www.ags.gov.ab.ca/publications/abstracts/OFR_2012_06.html> [May 2013].

Switzer, S.B., Holland, W.G., Graf, G.C., Hedinger, A.S., McAuley, R.J., Wierzbicki, R.A. and Packard, J.J. (1994): Devonian Woodbend-Winterburn strata of the Western Canada Sedimentary Basin; in Geological atlas of the Western Canada Sedimentary Basin, G.D. Mossop and I. Shetsen (comp.), Canadian Society of Petroleum Geologists and Alberta Research Council, p. 165–202.



Appendix 1 Sample Locations and Descriptions

Column Label Label DescriptionMap IDSite IDLocation - UWIWell NameLatitude NAD83Longitude NAD83Year DrilledNo. of Samples

D01 149532 100/06-14-037-07W5/00 CANHUNTER CHEDDARVILLE 6-14-37-7 52.178681 -114.895395 2009D06 66452 100/02-06-047-04W5/00 IMP CDN-SUP NORBUCK 2-6-47-4 53.020332 -114.571521 2008D07 70231 100/14-29-048-06W5/00 IMP CDN-SUP PEMBINA 14-29 BR- 48-6 53.176390 -114.845842 2008D10 82469 100/09-06-052-11W5/00 IMPERIAL CYNTHIA NO. 9-6-52-11 53.463004 -115.601615 2009D11 83772 100/10-30-053-14W5/00 HOME MOBIL PEERS 10-30-53-14 53.608763 -116.049330 2009D15 92284 100/10-09-059-11W4/00 SUN IOE LOTTIE 10-9-59-11 54.087511 -111.587683 2008D21 96975 100/10-13-063-12W5/00 IMP VIRGINIA HILLS 10-13-63-12 54.452329 -115.674185 2008D22 100906 100/10-05-065-15W5/00 MARATHON VIRGINIA HILLS 10-5-65-15 54.599662 -116.225665 2009D23 103988 100/04-33-068-22W4/00 IMPERIAL DEEP CREEK NO. 4-33-68-22 54.923841 -113.307416 2008D30 117592 100/11-17-088-03W6/00 PEX ET AL EUREKA 11-17-88-3 56.634242 -118.443537 2008D31 117603 100/02-30-088-04W6/00 TOTAL ATAPCO WORSLEY 2-30-88-4 56.656887 -118.620914 2009D34 184283 100/02-04-126-11W6/00 ESSO KAKISA 2-4-126-11 59.913369 -119.842205 2008D50 293507 100/12-12-057-22W5/02 TALISMAN 02 CECILIA 12-12-57-22 53.913120 -117.144736 2010

* Energy Resource Appraisal Group** Alberta Geological Survey

YearDrilled

LongitudeNAD 83

Map ID Location - UWI Well Name LatitudeNAD 83

Number of samples taken from core

Site ID

ERA* ID assigned for plotting sites on a mapAGS** ID used to uniquely identify oil and gas wells in AlbertaUnique well identifierName assigned to well when drilling beganWell location - degrees latitude, North American Datum 1983Well location - degrees longitude, North American Datum 1983Year well was drilled


8128 D30 100/11-17-088-03W6/00 2319.3 shale Muskwa8454 D23 100/04-33-068-22W4/00 1054.6 lime mudstone Duvernay8461 D15 100/10-09-059-11W4/00 797.7 lime mudstone Duvernay8481 D21 100/10-13-063-12W5/00 2625.5 calcareous shale Majeau Lake8492 D07 100/14-29-048-06W5/00 2655.7 calcareous shale Duvernay8995 D31 100/02-30-088-04W6/00 2401.2 shale Muskwa9210 D10 100/09-06-052-11W5/00 3020.1 calcareous shale Duvernay9226 D22 100/10-05-065-15W5/00 2752.0 shale Duvernay9238 D01 100/06-14-037-07W5/00 3649.7 shale Duvernay9362 D06 100/02-06-047-04W5/00 2639.6 calcareous shale Duvernay9367 D34 100/02-04-126-11W6/00 1517.4 shale Muskwa9392 D11 100/10-30-053-14W5/00 3172.8 shale Majeau Lake9645 D50 100/12-12-057-22W5/00 3881.7 shale Duvernay9651 D50 100/12-12-057-22W5/00 3884.7 shale Duvernay9658 D50 100/12-12-057-22W5/00 3894.8 shale Duvernay9663 D50 100/12-12-057-22W5/00 3902.1 shale Duvernay

* Alberta Geological Survey** Energy Resource Appraisal Group

Stratigraphic Unit

Map IDLocation UWISample Depth (Metres)Lithology

Name of stratigraphic unit at depth of sample

Sample ID Location UWI LithologyMap ID Sample Depth (Metres)

Column LabelSample ID AGS* sample number

ERA** ID assigned for plotting sites on a mapWell location - unique well identifierDepth of core sample in metres (measured from core)

Stratigraphic Unit

Label Description

Brief lithological description of sample


Appendix 2 Thin Section Descriptions

Legend

Column Label Label DescriptionSample ID AGS* sample identification numberMap ID ERA** ID assigned for plotting sites on a mapUWI Well location - unique well identifierStrat. Unit Name of stratigraphic unit at depth of sampleDepth Depth of core sample in metres (measured from core, uncorrected)Grain Size Size of the clastic grainsSand Grain size ≥ 62 µmUpper Silt Grain size 16-62 µm - including very coarse and coarse siltLower Silt Grain size 4-16 µm - including medium and fine siltClay Grain size ≤ 4 µmCement Secondary component that holds the grains together and/or occludes porosityAllochems Carbonate grains including lithoclasts, coated grains, peloids, aggregate grains, and skeletal grainsOrganics Constituents containing carbonOpaques Elements of the thin section that do not transmit light% The per cent of the constituent in the thin section.Variety (%) Type of constituent with its visually estimated per cent in bracketsRoundness Grain morphology - degree to which the grains have been smoothedSphericity Grain morphology - degree to which the grains have formed a spherical shapeSorting Measure of the spread of the grain-size distributionSedimentary Structures Spatial arrangement of the rock constituentsPrimary Sedimentary structures including erosional, depositional, and post-depositional structuresBiogenic Sedimentary structures including microbial mats and trace fossilsFractures Information about the fractures in the samplePorosity The visual estimation of space available to be occupied by liquids or gases in the sampleDescription Overall description of sampleThin Section Quality The physical quality of the thin section, including staining if it is present.Rock Classification Name of rock based on thin section using a variety of classification schemes* Alberta Geological Survey** Energy Resource Appraisal Group


Sample ID 8128Map ID D30 UWIStrat. Unit Depth

Grain Size % Variety (%) Variety (%) Variety (%) Variety (%) Variety (%)sand 0

upper silt 5 rock frag. (40) calcite (30) quartz (20) mica (10) plant matter?

lower silt 30 quartz (50) calcite (20) mica (20) rock frag. (10)

clay 52 clay/mud (60) quartz (20) mica (15) dolomite (5)

Cement 5 dolomite (100)

Allochems 2 calcispheres (100)

Organics 3 amorphous (100) plant matter?

Opaques 3 pyrite (100)100

RoundnessSphericitySorting

Sedimentary StructuresPrimaryBiogenic

FracturesPorosity

Description

Thin Section Quality

mediummoderately sorted

100/11-17-088-03W6/002319.3 mMuskwa Formation

subangular to subrounded

mudstone (Folk, 1974)

three prominent open horizontal fractures are a product of thin-section creationno porosity or microporosity observed

lenticular laminated, local clay lenses with disseminated pyritenone observed

Rock Classification

Some of the thin section is slightly too thick, but overall it is of fair quality; 1/2 stained for carbonates.

Lenticular laminated silty mudstone. The sample has a low amount of silt-sized grains that are mainly quartz, but some are calcite and some are rounded calcispheres. Thin horizontal lenses of clay-sized material are common and locally associated with increased pyrite. This thin section was re-polished; therefore, staining may have been polished away, leaving only faint staining in places. However, high relief and birefringence suggests more carbonate minerals. Minor amounts of organics are present as thin interlaminations and trace amounts of plant matter.


Sample # 8128, 100/11-17-088-03W6/00, 2319.3 m - Muskwa Formation

Plate 1: plane-polarized light. A low- to medium-magnification view showing lenticular laminated mudstone. Bedding orientation is displayed vertically in the image.

Plate 2: plane-polarized light. A medium-magnification view showing mudstone with local pyrite and round carbonate grains which may be micritic burrows. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A low- to medium-magnification view of a thicker portion of the slide showing rounded calcispheres. Bedding orientation is displayed horizontally in the image.

CALCISPHERES


Sample # 8128, 100/11-17-088-03W6/00, 2319.3 m - Muskwa Formation

Plate 5: plane-polarized light. A high-magnification view showing mudstone with organic material present as very thin, wispy laminations. Bedding orientation is displayed horizontally in the image.

Plate 6: plane-polarized light. A high-magnification view showing mudstone with minor disseminated pyrite. Most of the light coloured grains are quartz but some are dolomite. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A medium- to high-magnification view showing a lens of clay-sized minerals. These lenses are fairly common in the slide and sometimes are associated with an increase in disseminated pyrite. The clay-sized minerals are too fine grained for positive identification. Bedding orientation is displayed horizontally in the image.


Sample ID 8454Map ID D23 UWI 100/04-33-068-22W4/00Strat. Unit Duvernay Formation Depth 1054.6 m


upper silt 0

lower silt 0

clay 64 calcite (70) clay/mud (20) dolomite (10)

Cement 5 calcite (100)

Allochems 25 peloids (80) bioclasts (20)

Organics 5 algae spores (60) amorphous (40)


Sedimentary StructuresPrimary wackestone is massive, mudstone is finely laminated to wavy laminated Biogenic none observed

Fractures several carbonate-cemented vertical microfractures and two carbonate-filled discontinuous horizontal microfractures

Porosity no porosity or microporosity observed

DescriptionPeloidal wackestone and finely to wavy laminated carbonate mudstone. Approximately 50% of the slide is a very tight peloidal wackestone with scattered bioclasts and trace fossils. This wackestone is bordered on either side by a dark, thinly laminated carbonate mudstone with amorphous organic material, compressed marine algae spore cases, scattered thin lenses of coarser bioclastic debris, and sparry cement.

Thin Section QualityThe slide has uneven thickness throughout, slightly too thick in places; 1/2 stained for carbonates.

Rock Classificationpeloidal wackestone and mudstone (Dunham, 1962 cited in Embry and Klovan, 1972)fossiliferous micrite and micrite (Folk, 1974)


Sample # 8454, UWI 100/04-33-068-22W4/00, 1054.6 m - Duvernay Formation

Plate 1: plane-polarized light. A low-magnification view shows a sharp contact between very thinly laminated mudstone (right) and peloidal wackestone (left). Part of a bioclast (overexposed) is at lower right corner of image. Another thin bed of mudstone borders the wackestone to the left of the field of view. Bedding orientation is displayed vertically in the image.

Plate 2: plane-polarized light. A low- to medium-magnification view of an unstained, thicker portion of the wackestone showing groups of peloids. Bedding orientation is displayed vertically in the image.

Plate 3: plane-polarized light. A low- to medium-magnification view of an unstained portion of mudstone showing fine laminations and a lense of coarser material, predominantly bioclastic debris. Bedding orientation is displayed vertically in the image.


Sample # 8454, UWI 100/04-33-068-22W4/00, 1054.6 m - Duvernay Formation

Plate 5: plane-polarized light. A medium- to high-magnification view of unstained mudstone shows organic matter, possibly compressed marine algae spore cases (light yellow). They appear throughout the mudstone sections of the slide but not in the wackestone. Bedding orientation is displayed horizontally in the image.

Plate 6: plane-polarized light. A medium- to high-magnification view shows cemented vertical microfractures. This portion of the slide is unstained but the cement appears to be calcite. Bedding orientation is displayed vertically in the image.

Plate 4: plane-polarized light. A low- to medium-magnification view of a stained portion of wackestone, with an extremely fine vertical fracture with calcite cement. Similar fractures are in the unstained portion of the slide. Small patches of the slide did not stain. This could be a staining issue rather than selective dolomitization. A few of the unstained patches are associated with increased organics. Bedding orientation is displayed vertically in the image.

ALGAE SPORE CASES




upper silt 0

lower silt 0

clay 64 calcite (100)

Cement 25 bioclasts (90) fractures (10)

Allochems 5 peloids (100)

Organics 5 amorphous (90) algae spores (10)



FracturesPorosity

Description


sparse biomicrite (Folk, 1974)

Duvernay Formation

wavy laminatedminor bioturbation

Wavy laminated wackestone. The sample is wavy laminated and contains bioclastic debris, trace amounts of amorphous organics, algae spore cases, and peloids. Coarser laminations contain increased amorphous organic material (thin and wispy) and trace amounts of plant matter. Staining indicates that the majority of the mineral content is calcite.There are minor amounts of bioturbation.

100/10-09-059-11W4/00797.7 m

wackestone (Dunham, 1962 cited in Embry and Klovan, 1972)

one very fine vertical fracture that is filled with calcite cementno porosity or microporosity observed

Rock Classification

The slide is of fair quality; 1/2 stained for carbonates


Sample # 8461 - 100/10-09-059-11W4/00, 797.7 m - Duvernay Formation

Plate 1: plane-polarized light. A low-magnification overview of an unstained portion of the thin section with thinly laminated wackestone. Bedding orientation is displayed vertically in the image.

Plate 2: plane-polarized light. A medium-magnification view of an unstained portion of the slide shows a slightly coarser section of the slide. All of the white grains in the image are calcite, some are bioclastic others, are uncertain. Small lenses of organic matter can be seen scattered throughout the sample. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A medium-magnification view of an unstained portion of the slide exhibiting a much finer grained limestone compared to the two previous Plates. This is classified as mudstone (lime mudstone) with minor bioturbation and very little organic matter. Bedding orientation is displayed horizontally in the image.

ORGANIC MATTER



Plate 5: plane-polarized light. A high-magnification view showing very thin laminations of organic-rich material. Most of the organics in the slide are in wispy, discontinuous laminations within the coarser material, but some laminations, such as these, are continous over the length of the slide. Bedding orientation is displayed horizontally in the image.

Plate 6: plane-polarized light. A medium- to high-magnification view of a vertical fracture in the unstained portion of the slide. The fracture is predominantly cemented, possibly with calcite. Areas of the fracture that are not infilled could be original uncemented areas or may be the result of thin-section creation. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A medium- to high-magnification view of an unstained portion of the slide showing a very fine bioclastic wackestone. The reddish-brown in this image is organics mixed with possibly clays. Bedding orientation is displayed horizontally in the image.


Sample ID 8481Map ID D21 UWI 100/10-13-063-12W5/00Strat. Unit Majeau Lake Member Depth 2625.5 m


upper silt 0

lower silt 3 quartz (60) calcite (30) mica (10) feldspar (trace)

clay 89 clay/mud (60) quartz (30) mica (5) carbonate (5)

Cement 0

Allochems 0

Organics 3 amorphous (90) plant (10)


Sedimentary StructuresPrimary massive to lenticular laminatedBiogenic none observed

Fractures multiple very fine, open, horizontal microfractures, likely created during thin-section creation, indicates some natural fissility


DescriptionLenticular laminated claystone. The parallel orientation of organics and microfractures is a faint indication of bedding orientation. There is only a very small amount of lower silt-sized grains. Cement is ferroan calcite. Lack of staining of the clay-sized fraction suggests noncarbonate minerals. There is approximately 5% disseminated pyrite, minor amorphous organic material (as thin, wispy discontinous laminations and partings), and trace plant debris.

Thin Section QualityThere are two thin-sections, neither are of very good quality; one was 1/2 stained for carbonates

Rock Classificationclaystone (Folk, 1974)


Sample # 8481 - 100/10-13-063-12W5/00, 2625.5 m - Majeau Lake Member

Plate 1: plane-polarized light. A low- to medium-magnification shows extremely fine grained claystone with parallel, open, horizontal microfractures (created during thin-section creation). Bedding orientation is displayed horizontally in the image.

Plate 2: plane-polarized light. A medium-magnification view shows slightly silty claystone. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A high-magnification view shows slightly silty claystone with minor organic material present as thin, wispy, discontinuous laminations. Bedding orientation is displayed horizontally in the image.



Plate 5: cross-polarized light. A high-magnification view shows the presence of a carbonate mineral, possibly calcite. There is also a small percentage of clay-sized carbonate grains in the matrix, such as those seen in Plate 4. Bedding orientation is displayed horizontally in the image.

Plate 6: plane-polarized light. A medium- to high-magnification view, purposely overexposed to highlight the presence of opaques, mainly pyrite, which are disseminated throughout the thin section as small nodules. Some organic material is opaque in this image (thin, wispy laminae). Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A high-magnification view of a representative portion of the thin section. There is a relatively high pyrite content as well as the presence of clay-and silt-sized carbonate cement (see description of Plate 5 below). Bedding orientation is displayed horizontally in the image.




upper silt 5 quartz (60) calcite (35) mica (5) feldspar (trace)

lower silt 15 quartz (60) calcite (35) mica (5) feldspar (trace)

clay 70 clay/mud (80) quartz (15) mica (5)


Allochems <1 bioclasts (100)

Organics 3 amorphous (100)


Roundness subangular to subroundedSphericity medium to highSorting moderately sorted

Sedimentary StructuresPrimary finely laminatedBiogenic none observed

Fractures trace amounts of irregular, open microfractures, likely created during thin-section creation


DescriptionFinely laminated silty claystone. Silt-sized grains are predominantly quartz and ferroan calcite with some mica (muscovite). The matrix did not stain for carbonates. Organic material is also present throughout the sample in small amounts, mixed with other fine material. The sample has only trace microfractures that were likely created during thin-section creation. Trace bioclasts are present and include tentaculitids and brachiopod shell fragments.

Thin Section QualityThe thin section is of fair quality; 1/2 stained for carbonates.

Rock Classificationsilty claystone (Folk, 1974)



Plate 1: plane-polarized light. A low-magnification view shows finely laminated silty claystone. Lighter coloured laminations are composed of slightly coarser silt-sized grains with a decreased clay-sized content. The stained portions of the slide are slightly darker due to the presence of ferroan calcite (stained blue). Bedding orientation is displayed vertically in the image.

Plate 2: plane-polarized light. A medium-magnification view shows silty claystone with a lamination of slightly coarser silt. The lamination contains ferroan calcite cement (stained blue). Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A high-magnification view shows silty claystone with quartz grains, calcite and dolomite cements. Organic material is extremely fine, predominantly intermixed within the matrix. Bedding orientation is displayed horizontally in the image.



Plate 5: cross-polarized light. The same view as Plate 4 under cross-polarized light shows carbonate cement within the sample. Staining indicates that much is ferroan calcite, but there could be dolomite as well. Bedding orientation is displayed horizontally in the image.

Plate 6: plane-polarized light. A high-magnification view shows organics as thin wispy plates: most of the organic material in the sample is extremely fine and intermixed within the clay-sized material. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A medium- to high-magnification view shows silty claystone with a discontinuous silt lamination. Bedding orientation is displayed horizontally in the image.


Sample ID 8995Map ID D31 UWI 100/02-30-088-04W6/00Strat. Unit Muskwa Formation Depth 2401.2 m

Grain Size % Variety (%) Variety (%) Variety (%) Variety (%) Variety (%)sand trace quartz (100)

upper silt 2 quartz (100)

lower silt 5 quartz (80) mica (20)

clay 79 clay/mud (65) calcite (20) quartz (10) mica (5) dolomite (trace)


Allochems 0

Organics 4 amorphous (100) plant (trace)


Roundness subroundedSphericity mediumSorting well sorted

Sedimentary StructuresPrimary wavy laminatedBiogenic none observed

Fractures abundant open microfractures, most are horizontal and parallel, some are sub-horizontal and discontinuous, all were likely created during thin-section creation


DescriptionWavy laminated claystone. The sample is a claystone with minor detrital quartz and mica. A few quartz grains are very fine grained sand, but most are lower silt. Most of the sample is noncarbonate clay-sized minerals based on birefringence, habit, and lack of carbonate staining. The sample has abundant, open, parallel microfractures, likely created during thin-section creation. Trace amounts of organic material and relatively high pyrite content are distributed throughout the slide. There are also trace amounts of plant matter and a possible trace fossil. Organic-rich, discontinuous laminations have a parallel orientation, which is indicative of bedding orientation.

Thin Section QualityThe original slide broke and was remounted, very poor quality; 1/2 stained for carbonates.



Sample # 8995 - 100/02-30-088-04W6/0, 2401.2 m - Muskwa Formation

Plate 1: plane-polarized light. A low-magnification overview shows the poor quality of the thin section. The area in the middle of the image represents the most useable portion of the slide. There are abundant fractures created during thin-section creation. The bright white patch in the lower half of the slide is where material has been plucked or washed out. The condition of the slide suggests the presence of some water-sensitive clay minerals. Bedding orientation is displayed horizontally in the image.

Plate 2: plane-polarized light. A low- to medium-magnification view shows claystone with small amounts of detrital quartz. Most pyrite in the sample is much smaller than indicated in this view. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A medium-magnification view shows trace amounts of detrital quartz within the claystone, predominantly silt sized, but a few sand-sized grains are present. There is separation between the sample and the glass slide, which could indicate that clay minerals retained water after thin-section creation. The dark patch of clay-sized material could be abundant in swelling clay minerals. Bedding orientation is displayed horizontally in the image.



Plate 5: plane-polarized light. A high-magnification view shows disseminated pyrite. Bedding orientation is displayed horizontally in the image.

Plate 6: plane-polarized light. A medium-magnification view of a structure in a thick portion of the slide may be an infilled burrow. This section of the slide is unstained and too thick, but the mineral appears to be crystalline dolomite. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A high-magnification view shows a fairly representative portion of the slide. There is no evidence of carbonate staining. A sand-sized quartz grain is present. Euhedral crystals appear to be authigenic dolomite. There are minor amounts of organic material present as thin, wispy, discontinuous laminations and also trace amounts of plant matter. Bedding orientation is displayed horizontally in the image.


Sample ID 9210Map ID D10 UWI 100/09-06-052-11 W5/00Strat. Unit Duvernay Depth 3020.1 m


upper silt 0

lower silt 2 quartz (100)

clay 50 clay/mud (70) calcite (15) dolomite (15)

Cement 20 dolomite (60) calcite (40)

Allochems 25 tentaculitids (70) bioclasts (30)



Sedimentary StructuresPrimary very faint evidence of beddingBiogenic none observed

Fractures no fractures seenPorosity no porosity or microporosity observed

DescriptionWackestone. There is a significant amount of dark brown groupings of clay-sized grains, which does not seem to have stained; therefore, it is likely noncarbonate. Tentaculitid fragments up to 1 mm in longitudinal section and approximately 150 microns in cross-section are present along with other bioclastic material. Minor amounts of crystalline dolomite and calcite cement are present.

Thin Section QualityThere are 2 thin sections, both are too thick; one is 1/2 stained for carbonates.

Rock Classificationwackestone (Dunham, 1962 cited in Embry and Klovan, 1972)sparse biomicrite (Folk, 1974)



Plate 1: plane-polarized light. A low-magnification overview of an unstained portion of the slide shows wackestone. The most common fossils are tentaculitids. Also present are ostracod shell fragments. Bedding orientation is displayed vertically in the image.

Plate 2: plane-polarized light. A low- to medium-magnification view of an unstained portion of the slide shows tentaculitids and bioclastic debris (tentaculitid and ostracod fragments) within a clay-sized matrix with calcite and dolomite cements. Bedding orientation is displayed vertically in the image.

Plate 3: plane-polarized light. A medium- to high-magnification view of an unstained portion of the slide shows tentaculitids and other bioclastic debris within a clay-sized matrix, with calcite and dolomite cements. Bedding orientation is displayed vertically in the image.



Plate 6, plane-polarized light. A high-magnification view shows that the thin section has high clay-sized content. Only trace amounts of organics are present, some visible and intermixed with clay-sized material. Bedding orientation is displayed vertically in the image.

Plate 5: plane-polarized light. A medium- to high-magnification view of a stained portion of the slide shows a variety of cements. Most of the non-ferroan calcite is bioclastic debris while the ferroan calcite and dolomite appears to be a secondary cement. The stained portion of the slide is over-thick. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A medium- to high-magnification view of tentaculitids in the stained portion of the slide. The stained portion of the slide is over-thick. Ferroan calcite stains blue, non-ferroan calcite stains red. Some fossils also have minor dolomite replacement, locally ferroan. Bedding orientation is displayed horizontally in the image.

CLAY-SIZED


Sample ID 9226Map ID D22 UWI 100/10-05-065-15W5/00Strat. Unit Duvernay Depth 2752.0 m


upper silt 0


clay 82 clay/mud (55) calcite (30) mica (10) quartz (5)


Allochems 2 tentaculitids (80) bioclasts (20)



Sedimentary StructuresPrimary massive with parallel orientation of organicsBiogenic none observed

Fractures common parallel open microfractures assumed to be horizontal, a few are sub-horizontal and/or discontinuous; all are likely created during thin-section creation


Other NotesCalcareous claystone. The sample is extremely fine grained with only trace amounts of lower silt-sized grains (quartz and mica). A small amount of tentaculitid fossils are present. There is a ferroan calcite component, predominantly as silt-sized grains, some recognizable as bioclastic debris, and the rest probably a cement.

Thin Section QualityVery poor quality, original slide broke and was remounted on a second; 1/2 stained for carbonates.

Rock Classificationcalcareous claystone (Folk, 1994)



Plate 1: plane-polarized light. A low- to medium-magnification overview shows calcareous claystone with a large open fracture near the middle, partly infilled with rock flour. It is difficult to get good images because of the poor quality of the slide. Bedding orientation is displayed horizontally in the image.

Plate 2: plane-polarized light. A low- to medium-magnification view of the unstained portion of the slide shows a tentaculitid fossil and other bioclastic debris. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A medium- to high-magnification view of a stained portion of the slide shows claystone with a moderate ferroan calcite component (stained blue). Some calcite is bioclastic debris and some is cement. Bedding orientation is displayed horizontally in the image.



Plate 5: plane-polarized light. A medium- to high-magnification view of the stained portion of the slide shows the presence of ferroan calcite (faintly blue staining). Some larger grains can be identified as bioclastic debris, some may be cement. The hand sample has a strong reaction with HCl. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A high-magnification view of the unstained portion of the slide. The bulk of the sample is either dolomitic or noncarbonate with trace amounts of silt-sized quartz and mica, minor disseminated pyrite, and trace amounts of organic material. Bedding orientation is displayed horizontally in the image.




upper silt 0


clay 35 clay/mud (60) carbonate (40)

Cement 23 calcite (90) dolomite (10)

Allochems 36 calcispheres (80) tentaculitids (10) brachiopods (5) ostracods (5)

Organics <1 amorphous

Opaques 4 pyrite100

Sedimentary StructuresPrimary lenticular laminatedBiogenic minor bioturbation

Fractures trace amounts of open horizontal microfractures, likely created during thin-section creationPorosity no porosity or microporosity observed

DescriptionLenticular laminated wackestone. Sample has bioclastic debris (thin-shelled brachiopods, tentaculitids, and ostracods) and burrows, as well as trace amounts of amorphous organic matter. There are minor amounts of other silt-sized grains (quartz and possibly mica).

Thin Section QualityTwo thin sections: one is of fair quality and 1/2 stained for carbonates; the other is too thick.




Plate 2: plane-polarized light. A medium-magnification view shows a micritic lens. This portion of the slide is unstained, but similar features in the stained portion of the slide confirm the burrows are infilled with micrite. Bedding orientation is displayed horizontally in the image.

Plate 1: plane-polarized light. A low-magnification view of a stained portion of the slide is a wackestone, showing fossils possibly including tenticulitids, calcispheres, thin-shelled brachiopod fragments, and ostracods. Bedding orientation is displayed vertically in the image.

Plate 3: plane-polarized light. A medium-magnification view of an unstained portion of the slide showing fossils including tentaculitids and calcispheres. Bedding orientation is displayed horizontally in the image.

MICRITIC LENS



Plate 6: plane-polarized light. A high-magnification view shows abundant calcareous grains. Almost all of the light-coloured grains are calcite; only a trace amount of quartz and dolomite are present. Bedding orientation is displayed horizontally in the image.

Plate 5: plane-polarized light. A high-magnification view of an unstained portion of the slide showing abundant grains, mostly calcareous. The dark, clay-sized material did not appear to stain; therefore, it is likely a mixture of noncarbonate minerals. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A medium- to high-magnification view of an unstained portion of the slide showing abundant grains, mostly calcareous. Almost all light-coloured grains are calcite, some are identifiable as bioclastic debris, and some of the smaller grains may be secondary cement. Bedding orientation is displayed horizontally in the image.




upper silt 0


clay 61 calcite (60) clay/mud (35) quartz (5) dolomite (trace)

Cement 5 dolomite (90) calcite (10)

Allochems 23 tentaculitids bioclasts



Sedimentary StructuresPrimary thinly bedded, lenticular laminatedBiogenic none observed

Fractures trace irregular, horizontal open microfractures likely created during thin-section creationPorosity no porosity or microporosity observed

DescriptionThinly bedded, lenticular laminated wackestone. The thin section is very thin, and the carbonate staining is difficult to interpret, but it appears that some of the dark clay-sized matrix did stain as calcite. Allochems include calcareous fossils of tentaculitids, brachiopod shells, and other bioclastic debris. Smaller calcareous grains may be bioclastic debris as well; some may be cement. There are trace amounts of silt-sized quartz, as well as minor amounts of crystalline dolomite. Evidence of parallel bedding with increased allochems in coarser laminations.

Thin Section QualityThin section is of fair quality, too thin in places; 1/2 stained for carbonates.




Plate 1: plane-polarized light. A low-magnification overview of the unstained portion of the slide shows a lamination with increased fossils within a wackestone matrix. Bedding orientation is displayed horizontally in the image.

Plate 2: plane-polarized light. A medium-magnification view shows the two major fossils present in the slide, both tentaculitids. This portion of the slide is unstained. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A medium- to high-magnification view of an unstained portion of the slide, which is representative of most of the slide: a bioclastic wackestone. Bedding orientation is displayed horizontally in the image.



Plate 5: plane-polarized light. A high-magnification view of an unstained portion of the slide. Representative of much of the slide, it shows abundant calcareous grains, trace amounts of silt-sized quartz within a matrix of a mixture of clay-sized carbonate minerals, clays, organics, and possibly other minerals. Bedding orientation is displayed horizontally in the image.

Plate 6: plane-polarized light. A high-magnification image of a stained portion of the slide shows bioclastic debris, calcareous grains, and trace amounts of silt-sized quartz within a clay-sized matrix. The matrix is difficult to identify, but it is stained red (indicating calcite), and there are also organics and clays intermixed. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A medium- to high-magnification view of a stained portion of the slide showing a bioclastic wackestone with trace amounts of silt-sized quartz. This stained portion of the slide is very thin and some components were dissolved by the staining agents. Bedding orientation is displayed horizontally in the image.

CLAY-SIZED/ORGANICS


Sample ID 9367Map ID D34 UWI 100/02-04-126-11W6/00Strat. Unit Muskwa Depth 1517.4 m


upper silt 0


clay 80 clay/mud (85) mica (10) quartz (5)


Allochems 0



Sedimentary StructuresPrimary lenticular laminated to massive, some evidence of soft sediment deformationBiogenic none observed

Fractures several irregular horizontal and subhorizontal, open microfractures, likely created during thin-section creation


DescriptionLenticular laminated to massive silty claystone. The detrital grains are quartz and mica. There are also minor amounts of dolomite, probably a secondary cement. Pyrite is distributed throughout the sample, with large nodules in some areas. Minor amounts of organic material are present as thin, wispy interlaminations. There are several open microfractures that are approximately parallel to lamination orientation. The sample is moderately to well consolidated.

Thin Section QualityThin section is of fair quality; 1/2 stained for carbonates.




Plate 2: plane-polarized light. A low- to medium-magnification view shows slightly silty claystone. The light-coloured grains are either quartz, authigenic dolomite, or mica. Bedding orientation is displayed horizontally in the image.

Plate 1: plane-polarized light. A low-magnification view shows claystone with irregular, open microfractures. They are close to parallel with lamination orientation. The microfractures were likely a product of thin-section creation. The near-vertical lines in the image are scratch marks on the underside of the sample. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A medium- to high-magnification view shows slightly silty claystone. The matrix is too fine to identify individual minerals. Bedding orientation is displayed horizontally in the image.



Plate 6: plane-polarized light. A high-magnification view shows a claystone. The matrix, which is the bulk of the sample, is a mixture of clay-sized minerals. Bedding orientation is displayed horizontally in the image.

Plate 5: plane-polarized light. A high-magnification view shows slightly silty claystone with trace organics as thin, wispy interlaminations. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A medium- to high-magnification view shows pyrite nodules, which are distributed throughout the slide. A few nodules in the slide are close to 0.5 mm in length. Bedding orientation is displayed horizontally in the image.


Sample ID 9392Map ID D11 UWI 100/10-30-053-14W5/00Strat. Unit Majeau Lake Member Depth 3172.8 m


upper silt 0

lower silt 1 quartz (trace) mica (trace)

clay 77 clay/mud (60) calcite (35) mica (5) pyrite (trace)


Allochems 4 calcispheres (60) bioclasts (40)

Organics <1 amorphous (100)


Sedimentary StructuresPrimary massiveBiogenic none observed

Fractures horizontal, open microfractures; irregular, branching, discontinuous in sections, likely a result of thin-section creation


DescriptionMassive calcareous claystone. The sample has moderate amounts of ferroan calcite in the form of cement and bioclastic debris. The clay-sized matrix does not stain for carbonates. There are scattered microfossils, which are predominantly calcispheres. Pyrite frambroids distributed throughout the sample, and in some areas they have a higher concentration in coarser-grained lenses. There are trace amounts of amorphous organic material.

Thin Section QualityThis thin section is fair quality; 1/2 stained for carbonates.




Plate 1: plane-polarized light. A low-magnification view of an unstained portion of the slide shows massive claystone with calcisphere microfossils. The area between the annotated lines is part of a lens that has increased pyrite. Bedding orientation is displayed horizontally in the image.

Plate 2: plane-polarized light. A low- to medium-magnification view shows a claystone with a calcite-filled calcisphere and other bioclastic debris. Nearly all of the light-coloured grains in the image are calcite. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A medium- to high-magnification view of a stained portion of the slide shows ferroan calcite within a clay-sized matrix. Both detrital and authigenic calcite grains are present. Bedding orientation is displayed horizontally in the image.



Plate 5: plane-polarized light. A high-magnification view of a stained portion of the slide shows ferroan calcite (stained blue) within an unstained clay-sized matrix. Bedding orientation is displayed horizontally in the image.

Plate 6: cross-polarized light. A high-magnification view shows that many minerals in the matrix have a high birefringence. It appears that this is the ferroan calcite component: the bulk of the clay-sized fraction remains unidentifiable. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A high-magnification view of an unstained portion of the slide shows calcite in the form of bioclastic debris and cement. Bedding orientation is displayed horizontally in the image.

CLAY-SIZED MATRIX




upper silt 0

lower silt 6 quartz (40) mica (40) calcite (20)

clay 71 clay/mud (50) calcite (20) quartz (20) mica (10)


Allochems <1 tentaculitids bioclasts



Sedimentary StructuresPrimary massive with vague laminationsBiogenic none observed

Fractures open microfractures, branching and apparently parallel to bedding, likely created during thin-section creation


DescriptionMassive calcareous claystone. Carbonate staining indicates that most of the carbonate minerals are ferroan calcite. The sample is dominantly comprised of microcrystalline and clay-sized grains. There is a small amount of silt-sized quartz and mica present, as well as bioclastic debris including tentaculitids and other shell fragments. The clay-sized portion of the sample is composed of clay minerals, quartz, minor amounts of mica, and minor amounts of intermixed organics and clays. There are several open horizontal microfractures, likely created during thin-section creation.

Thin Section QualityThin section is of fair quality, slightly thick in the middle; 1/2 stained for carbonates.



Sample # 9645 -100/12-12-057-22W5/00, 3881.7 m - Duvernay Formation

Plate 1: plane-polarized light. A low-magnification overview shows predominantly massive claystone with open microfractures. The majority of them are parallel to bedding (horizontal). Fractures are from thin-section creation. Bedding orientation is displayed horizontally in the image.

Plate 2: plane-polarized light. A medium-magnification view shows claystone with bioclasts, including tentaculitids. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A medium- to high-magnification view of a stained portion of the slide shows common presence of ferroan calcite, much of which is in the clay-sized fraction. Most of the light-coloured grains are calcite (stained blue), with only minor amounts of quartz grains. Bedding orientation is displayed horizontally in the image.


Sample # 9645 -100/12-12-057-22W5/00, 3881.7 m - Duvernay Formation

Plate 5: plane-polarized light. A high-magnification view shows claystone with calcite cement. Bedding orientation is displayed horizontally in the image.

Plate 6: cross-polarized light. A high-magnification view shows some calcite as light-coloured grains. Based on the stain, most of the carbonate content is ferroan calcite. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A high-magnification view of a stained portion of the slide shows ferroan calcite (stained blue) and minor amounts of quartz, within a predominantly clay-sized matrix. There appears to be minor amounts of organic material within the clay-sized matrix. Bedding orientation is displayed horizontally in the image.




upper silt 4 calcite (60) quartz (30) mica (10)

lower silt 10 calcite (60) quartz (30) mica (10)



Allochems 1 bioclasts (100)



Roundness subroundedSphericity mediumSorting moderately sorted

Sedimentary StructuresPrimary massive with faint beddingBiogenic none observed

Fractures two calcite-infilled fractures (assumed vertical) are natural; several open fractures (assumed horizontal) are likely created during thin-section creation


DescriptionMassive calcareous silty claystone. The stain for carbonates is somewhat ambiguous, but it appears that most of the carbonate minerals are ferroan calcite with minor amounts of dolomite. There are only trace amounts of silt-sized grains. There are clay-sized quartz grains present. Two calcite-cemented fractures are observed, both are vertical based on faint indications of bedding in the sample. There are only trace amounts of silt- and sand-sized bioclastic debris as well as amorphous organics intermixed with clay-sized material.

Thin Section QualityThin section is of fair quality, uneven thickness, sample size is small; 1/2 stained for carbonates.

Rock Classificationcalcareous silty claystone (Folk, 1974)



Plate 1: plane-polarized light. A low- to medium-magnification overview shows a massive calcareous silty claystone and a calcite-infilled fracture. Areas within the annotated rectangles are alignments of grains that may indicate the horizontal plane, which would suggest that the fracture is almost vertical. The thin section is slightly too thick in this image. Bedding orientation is displayed horizontally in the image.

Plate 2: plane-polarized light. A medium-magnification view shows a network of infilled fractures, the most prominent (on the left) is present through the length of the slide. Infilled fractures annotated as "1" are infilled with what appears to be ferroan calcite, with trace amounts of quartz crystals within the calcite. The area annotated as "2" is a microfault. The thin section is slightly too thick in this image. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A high-magnification view shows claystone with trace amounts of mica. Almost all of the light-coloured grains are calcite but, there are clay-sized quartz grains present as well. It appears that there are minor amounts of amorphous organics intermixed with the clay-sized material. Bedding orientation is displayed horizontally in the image.

CLAY-SIZED MATERIALAND ORGANICS



Plate 5: cross-polarized light. The same view as Plate 4 under cross-polarized light shows most of the carbonate content as light-coloured grains. Staining indicates that most of the carbonate content is ferroan calcite. Bedding orientation is displayed horizontally in the image.

Plate 6, plane-polarized light. A high-magnification view shows an unstained portion of the slide. Most of the light-coloured grains in the image are calcite. There are also trace amounts of silt-sized quartz and minor amounts of clay-sized quartz. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A medium- to high-magnification view shows calcareous claystone. This is an unstained portion of the slide.




upper silt <1 mica (100) quartz (trace)




Allochems trace bioclasts (100)



Roundness subroundedSphericity mediumSorting well sorted

Sedimentary StructuresPrimary massive, but the sample is highly fragmentedBiogenic none observed

Fractures natural extremely fine microfractures filled with ferroan calcite cement; sample is badly fractured/fragmented from thin-section creation


DescriptionMassive calcareous silty claystone. The sample has minor amounts of lower-silt-sized quartz and mica. Staining indicates that most of the carbonate minerals are ferroan calcite, but minor amounts of dolomite are also observed. Trace amounts of bioclastic debris are present, as well as trace amounts of amorphous organics intermixed with clays. Although most of the extensive fracturing is attributed to thin section preparation, there are at least two extremely fine natural microfractures filled with ferroan calcite cement.

Thin Section QualityThin section is of poor quality, sample is badly fragmented; 1/2 stained for carbonates.

Rock Classificationcalcareous silty claystone (Folk, 1974)



Plate 1: plane-polarized light. A low-magnification overview shows the fragmented condition of the slide. The large fractures are a result of thin-section creation. Bedding orientation is displayed horizontally in the image.

Plate 2: plane-polarized light. A medium- to high-magnification view of the stained portion of the slide shows calcareous silty claystone. Staining indicates that most of the carbonate minerals are ferroan calcite. There does appear to be a minor dolomite content as well. Many of the calcite grains are clay-sized. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A medium- to high-magnification view shows a very fine microfracture assumed to be horizontally oriented and filled with ferroan calcite cement (annotated as "1"). Another parallel fracture is open (annotated as "2"). The slide is over-thick where this image was taken. Bedding orientation is displayed horizontally in the image.



Plate 5: plane-polarized light. A high-magnification view shows slightly silty claystone. The dark brown matrix is predominantly clay minerals with trace amounts of organic material intermixed. Bedding orientation is displayed horizontally in the image.

Plate 6: plane-polarized light. A high-magnification view of an unstained portion of the slide shows slightly silty claystone. Silt-sized quartz is present, but most of the quartz grains in the sample are clay-sized. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A high-magnification view shows a prominent, open, horizontal microfracture in the centre. This fracture was created during thin-section creation. Within the annotated rectangle there is a microfracture filled with ferroan calcite cement. This fracture is extremely fine and difficult to see, even at the highest magnification. Some of the fractures in the sample, which result from thin-section creation, formed along these extremely fine, infilled fractures. Bedding orientation is displayed horizontally in the image.




upper silt trace calcite (55) quartz (45) mica (trace)


clay 81 calcite (40) clay/mud (40) quartz (15) mica (5)

Cement 5 calcite (100) dolomite (trace)

Allochems trace tentaculitids bioclasts



RoundnessSphericitySorting


FracturesPorosity

Description


calcareous claystone (Folk, 1974)

open microfractures (assumed horizontal), trace amounts of vertical microfracturesno porosity or microporosity observed

Rock Classification

Thin section is fair quality; 1/2 stained for carbonates.

Lenticular laminated calcareous claystone. Grains are predominantly silt- and clay-sized calcite, quartz, and mica. Staining indicates that most of the carbonate minerals are ferroan calcite. Open microfractures parallel to laminations are common, and some have an opaque lining (possibly organic material). It is difficult to determine if this is a fracture lining or part of the pre-existing rock fabric. Only trace amounts of bioclastic debris are present, including tentaculitids and shell fragments. There are trace amounts of organics in the form of thin, wispy plates intermixed with clays. The sample fractured along planes of weakness during thin-section creation.

none observed

subroundedmediumwell sorted

100/12-12-057-22W5/003902.1 mDuvernay Formation

faintly lenticular laminated



Plate 1: plane-polarized light. A low- to medium-magnification view shows calcareous claystone with minor amounts of open microfractures. There are faint indications of bedding, and most of the microfractures are parallel to bedding. Bedding orientation is displayed vertically in the image.

Plate 2: plane-polarized light. A medium- to high-magnification view of claystone shows light-coloured calcite and quartz grains. Staining indicates that most of the carbonate minerals are ferroan calcite. Quartz is present as silt- and clay-sized grains. Bedding orientation is displayed horizontally in the image.

Plate 3: plane-polarized light. A high-magnification view shows slightly silty calcareous claystone. The dark brown matrix may be clays intermixed with organic material. Bedding orientation is displayed horizontally in the image.



Plate 5: plane-polarized light. A high-magnification view shows a very fine, open microfracture that appears to be lined with organic material. The organic matter would have presented a plane of weakness for fracturing durring thin-section creation. Bedding orientation is displayed horizontally in the image.

Plate 6: plane-polarized light. A high-magnification view shows intersecting open microfractures. As discussed in the description of Plate 5, there appears to be a relationship between the presence of organics and the open microfractures. This image was taken over a stained portion of the slide; ferroan calcite is stained blue. Bedding orientation is displayed horizontally in the image.

Plate 4: plane-polarized light. A high-magnification view shows what appears to be organic material present in the form of wispy plates, although they are too fine to positively identify with a standard petrographic microscope. Bedding orientation is displayed horizontally in the image.

ofr 2013-06 thin section analysis of core samples from the duvernay and muskwa formations and the...

Documents

albertaaerags open file

right of alberta

majeau lake member

muskwa formations

section preparation

sample descriptions

secondary structures

sample locations